PANAMIC-PACIFIC PELECYPODA J« 



angled posterior keel, and rich coloration. D. striatus Linne of the Caribbean 

 is a somewhat similar species but smaller, shorter, and more solid, color 

 usually white. 



Range — Mexico to northern Peru. Mexico: San Bias; Mazatlan. 

 Nicaragua: Corinto (H. and S.). Panama: Panama City; Guanico. Colom- 

 bia: Tumaco; Isla del Gallo. Ecuador: Ancon Point; Santa Elena; Char- 

 apota; Sua; Esmeraldas; Camarones. Peru: Tumbez; Zorritos; Mancora. 



Donax peruTianns Deshayes Plate 60, figures 2-2e 



Donax radiatus Valenciennes, 1817, Humboldt et Bonpland, Recueil d'Observations de 



Zoologie, vol. 2, pp. 221, 222, pi. 50, figs. 3, a, b, c, et fig. 4. Not D. radiatus 



Gmelin, 1791. 

 Donax perwvianus Deshayes, 18S+, Proc. Zool. Soc. London, pp. 350, 351.— Romer, 



1870, Syst. Conch. Cabinet., vol. 29, p. 55, No. 32, pi. 9, figs. 18-20. 

 Donax aricana Dall, 1909, Proc. U.S. Nat. Museum, vol. 37, No. 1704, p. 273. New 



name for D. radiatus Val. 



The valves are subelliptical, subtrigonal, convex, the beaks placed near 

 the posterior one-third and with a low or moderate inflation continued along 

 the umbonal slope downward to form a slight bulge in the ventral margin 

 near the middle point. The anterior side is longer, narrower, rounded at 

 the end, the posterior side with a gentle slope into the narrowly rounded 

 or subtruncated end. The surface is nearly smooth except for narrow radial 

 lines which show quite plainly except in shells which have a pure white 

 color. 



Length 33.7 mm., height 20 mm., diameter 16.4 mm. Negritos, Peru. 



In shape, this species is similar to D. punctato striatus except that it 

 is usually a little longer and the surface is smooth without interradial punc- 

 tation. The surface color is usually an ivory white or a pale mauve, some- 

 times a pale yellow and often with unequal rays of violet across the middle. 

 This is the common beach Donax of Peru ranging southward into Chile. 

 It is often seen in the markets and it was consumed in large quantities by 

 the Peruvian Indians in pre-Colonial times, judging by the abundance of 

 its shells over their burial places. Santa Elena Peninsula of western Ecuador 

 appears to be its northern limit of range; a few valves in my collection from 

 there are unusually large (length 40 mm.). 



Range — Santa Elena Peninsula, Ecuador to Chile. Ecuador: Santa 

 Elena. Peru: Zorritos; Mancora; Lobitos; Negritos; Paita; Sechura; Chi- 

 clayo; Chimbote; Mollendo (Weyrauch). 



Donax asper Hanley Plate 59, figures 1-ld 



Donax asper Hanley, 1845, Proc. Zool. Soc. London, pt. 3, p. 14 Tumbez, Peru.— 

 Reeve, 1854, Conch. Icon., vol. 8, Donax, pi. 2, fig. 12.— Sowerby, 1866, Thes. 

 Conch., vol. 3, Donax, p. 307, No. 16, pi. 280, fig. 24.— Dall, 1909, Proc. U.S. 

 Nat. Museum, vol. 37, No. 1704, p. 159, pi. 28, fig. 7. — Hertlein and Strong, 

 1949, Zoologica, vol. 34, pt. 4, pp. 251-252. 



Shell large, exceeding 30 mm. in height, trigonal, generally solid, the 

 umbones gibbous and elevated above the hinge margin, the posterior side 

 strongly flattened and truncated, the anterior side longer, somewhat nar- 

 rowed, and rounded at the end. Radiating riblets are fine, closely spaced 

 and trellized by crossthreads on the posterior slope but without a sub- 



